Lens for automobile headlights



Nov. 16 1926. y 1,607,084

F. A. KENNEY LENsFoR vAUTOMOBILE HEADLIGHTS A Filed may 2e. 192s www attoz um;

Patented Nov. 1 6, 19.26. l l

`ogniz/ed and many waysof overcoming the .UNITED STATES .PATENT oFFlcE.

'V LENS non AUTOMOBILE HEADLIGHTS. i

This invention relates to improvements in is so constructed that 'it causes the light rays- I systems of automobile illumination and has to be directed downwardlyupon-the road Areference more particularly t0 the construcway quite close tothe front of the car land tion of the lenses for the headlights. j

The headlights'that are almostuniversally- This lamp gives a satisfactory illumination used on automobiles for road illuminationv for slow driving or on good safe roads. have several objectionable features among The left hand lamp isprovided with a simiwhich mention may be made of the fact that lar lens that throws the light farther ahead they project rays of llight upwardly in such and has a smaller angle of spread. This a direction that they cause a glare 'that lamp gives the light required forlfast drivblinds the drivers of approaching automoing. As the light from the lefthand lamp biles 'and often cause serious accidents to may beobjctionable to the drivers of maoccur.l A 1 p f, chines traveling in the oppositedirectiomit The objectionable features of the present is preferable to provide a switch for dimautomobile illumination have long been recming one or both of the lamps.

same have been proposed, none of which, of lenses that I have illustrated on the `achowever, have been universallyadopted. T companying drawings and which I will now It is obvious that the only light that is v proceed to describe in detail', referencer for usefully employed is the light 4that strikes this purpose being had to the drawing inV the surface of the road and that therefore which:

' strike the road surface to make the road visnated the required distancekahead of the authat portion ofthe light that is projected Fig. 1f is a view of the rear surface of the 'f upwardly serves no useful purpose whatleft hand lens; ever, but is merely a source of' danger, for I Fig. 2 is 'a vertical section taken on' line reasons already explained. 2- -2, Fig. l;

Proper road illumination not 'only re-A Fig. 3 is Ma quires ,thata sufficient amount of light shall taken on line 3 3, Fig. 1';

ible but it also requires a proper distribution. right hand -lens The road surface directlv `in front lof the l car should be well illuminated so that they taken on line 5:-5, Fig. 4; driver may see any defects 'in the road in `Fig. 6 is a'horlzontal `diarnetrical section time'to' avoid them.. In addition` to this itv taken online 6 6, Fig. 4;

is quite necessary, especially for fast driv- Fig. 7 is a diagrammatic plan view showing, that the road shall be fairly wellillumi ing the horizont-al distribution of the light natedfor a lconsiderable distance in front of 'upon' the road, and

the car so that the driver may see otherve- Fig. 8 isa view showing the distribution hicles or pedestrians in time to avoid the-of light in a vertical plane, the right hand same and so that turns inthe road may be lamp being shown as if it were on alower perceived in time to makethe necessary preplevel thanthe left hand arations. Where the road is to be illumiof clearness.

tomobile, it is. sometimes very difficult to right and"left hand headli'hts of theautoavoid objectionable glare as the road surface mobile by the Vletters R an L respectively,`

is often undulating to such an extent that and the corresponding lenses as RL and LL.

lightthat would be satisfactory on alevel The lenseslare both similar in appearance w road will be highly objectionable at times. and are' each provided'with a4 group ofcon- It is therefore very difficult tosecureproper centric prisms which have been designated road illumination by means of a single lampv by the letter A... vThese prisms are vall loor two lamps havingan identicalv distribuf catedv above the diameter of the -lens and tion of light. Q f taper upwardly so as to refract the light in to spread the light over the entire roadway.-

I have embodied my invention in a pair` horizontal diametrical section.

Fig. 4 is a view of therear surface ofthe f Fig. 5 is -a vertical diametrical section lamp for the purpose ln the drawing l have designated the It' is the object of this invention to .proa downward direction. Another grouplof duce a system of illumination employing two arcuate prisms which I have designated by lamps each provided with a lens that gives the letter B occupies the lower portionof a specifically different distribution of light. each lens. These prisms also. taper up# he lens lemployed on the right hand lamp wardly. vIntermediate the `two groups ofv taper upwardly. -It will be noted from closer to the automobile.

Figs. 2 and 5 that the prisms on the-right lens have a greater upward taper than those of the left lens, so that it will refract the light downwardly at a greater angle than the left lens. The two horizontal prisms C have their rear surfaces corrugated in a vertical direction. Referring now more particularly 'to Figs. 3 and 6, it will be noticed that theucorrugations on the prisms C of the right lens are deeper than those vof the left lens, whereby they effect a more Q pronounced lateral distribution of the light,

in the manner indicated in lFig. 7. 'lhe refractive power of the prisms A, B and C mustbe suflicient tokeep the light rays down within the llegal requirements. rlihe light that passes through the rigbtlens is bent downwardly at a sharper angle than the light that passes through the left hand lens and will therefore strike the roadway That part of the ,light that passes through the prisms FC of the right lens will be spread laterally at a considerable angle, sofas to illuminate the right side lof the road and also spread some distance to the left of the maehiiie. rlhe distribution of light from the right lens is suitable for city driving, or-on good roads and where the car travels at a lmoderate speed. On country roads and where ia high speed is 55 luminationof the r maintained, it is necessary to illuminate the lroad a farther distance ahead and this is accomplishedv ,by the `left hand lamp whose prisms have smaller angularity. When meeting tratlic instead of dimming both lamps in the manner now commonly done, the left lamp only may be dimmed 'or turned ,0E entirely. This leaves the. right handlamp at its full strength ywhich gives a good illumination of the 'roadwayswithout interfering in any way with the vision of Yapproaching qdrivers. y

lit will be apparent from the explanation given abovethat the effect produced is due sto the combined action of the two derent lenses 'which cooperate t `nd lens has prisms with greater angularity which refract the light downwardly 'at a greater .angle than 4the .left lens. This causes agreater sidewise dispersion of the slight so that the right lamp alone gives a good ilway immediatelyin front ofthe car and fo some distance ahead.

arrangement of the three groups of prisms.v

The horizontal prisms C- being 'located slightly below the center of the lens projects awide lband of light onto the roadway and diffuses the same by the action of the vertical corrugations. From Figs. 3 and 6 it will be seen that the vertical corrugations on the horizontal prisms C are different in the middle than at the ends so as to permit the light to .be given a better distribution.

Having now described my invention what li claim as new is:

1.- An automobile headlight lens compusing, in combination, a circular lens having one surface plain and the other surface provided with two groups of arcuate prisms, one of said groups being located vin the top portion of lena-the other being located in the bottom portion, said prisms being. up# wardly tapered, and concentric with the lens, and a group of straight -horizontal Nprisms located between the 'two groupsfof arcuate prisms, the horizontal prisms being crossed with vertical corrugations.

2. A pair of lenses having arcuate prisms in the upper portions ofthe lenses, horizontal 1 prisms in the middle portions, vertical Huted ksurfaces on vthe. horizontal prisms, arcuate prisms in` the bottom portions of lenses, one of the lenses having light vre,-

fracting elements of lgreater refracting power thanthe other lens, the bases of all of -said yprisms being directed downwardly.

3. An automobile headlight lens having arcuate` prisms at the bottomv portion, projecting a beam of light diverging from the center, horizontal prisms crossedby vertical iuted surfaces through the middle portion for deflecting the light downward-and dispersing it laterally, arcuate prisms in the upper portions ,of the lexis projecting a beam with its rays converging toward fthe center of the lens.

lin testimony whereof l aiiix my signature.

\ FRANK A. KENNEY. 

